A dual-fluorescence biosensor based on metal ion regulation of copper nanoclusters for NSCLC exosome detection

Early diagnosis and treatment can significantly enhance the prognosis of patients with non-small cell lung cancer (NSCLC); however, current diagnostic methods remain plagued by inadequate sensitivity or excessive invasiveness. This study describes the innovative construction of a dual-fluorescence, dual-target biosensor based on copper nanoclusters (CuNCs) and hollow mesoporous silica nanospheres (HMSNs) for highly sensitive detection of CD91 and CD151 on the surface of NSCLC exosomes. Specifically, HMSNs regulate the fluorescence signals of red and blue glutathione-CuNCs by loading Ce 3+ and Fe 3+ and conjugating a pH-responsive chitosan coating: Ce 3+ significantly enhances the fluorescence signal of red CuNCs by inducing their aggregation, whereas Fe 3+ quenches the fluorescence signal of blue CuNCs through oxidation. Exosomes are captured using a CD63 aptamer conjugated to streptavidin magnetic beads. HMSN-Ce 3+ -CS-antiCD151 and HMSN-Fe 3+ -CS-antiCD91 probes are then employed to target exosome surface proteins CD151 and CD91, respectively, allowing synchronous detection of dual-fluorescence and dual targets. We then measured and analyzed the change ratio of fluorescence signals, and optimized the detection parameters while evaluating the sensitivity, stability, and linear range of the system. The detection limits of red and blue fluorescence systems were 1058 particles·mL −1 and 239 particles·mL −1 , and ranges of linearity were 4 × 10 3 –4 × 10 8 particles·mL −1 and 7 × 10 2 –7 × 10 6 particles·mL −1 , respectively. Overall, this study introduces a novel strategy for the early screening of NSCLC, with high sensitivity and minimal invasiveness. The complementary design of the dual-fluorescence system extends its detection range and holds potential for clinical application.